The influence of the developmental host plant complex on future foraging behavior in Lysiphlebus testaceipes (Hymenoptera: Braconidae)

This study examines whether the host plant complex from which the generalist aphid parasitoid Lysiphlebus testaceipes (Hymenoptera: Braconidae) develops influences future foraging behavior by the parasitoid.  It has been demonstrated that aphid parasitoids can learn host plant complex cues during development and adult emergence, which can influence foraging decisions.  In this experiment, L. testaceipes are reared from Aphis glycines (Hemiptera: Aphididae) on soybean (Glycine max) or from Rhopalosiphum padi (Hemiptera: Aphididae) on barley (Hordeum vulgare). In the choice scenario, in which parasitoids were presented with 50 A. glycines individuals on soybean and 50 R. padi individuals on barley together in a caged pot, parasitoids developed from R. padi parasitized an average of 25.1 (SE+/-2.2) R. padi individuals and 12.4 +/- 2.4 A. glycines individuals (n=23).  Parasitoids developed from A. glycines parasitized 26.8 +/- 2.7 R. padi individuals and 17.7 +/- 2.5 A. glycines individuals (n=23).  In the no choice scenario, in which parasitoids were presented with 100 individuals of a single aphid species on a caged host plant, parasitoids developed from R. padi parasitized an average of 41.1 +/- 5.2 R. padi individuals (n=11), and 45.6 +/- 4.9 A. glycines individuals (n=22).  Parasitoids developed from A. glycines parasitized 55.4 +/- 3.0 R. padi individuals (n=11), and 49.1 +/- 3.2 A. glycines individuals (n=22).  Sex ratio of offspring and pupal mortality are also reported.  Evidence does not suggest that the efficacy of L. testaceipes against A. glycines is improved by prior experience with this pest’s host plant complex.